A small blog for marine navigation, astronomy, space exploration, Project Orion (DARPA's "100-year starship"), meteorology, boating and matters pertaining to maritime education and the maritime industry.
I am a USCG licensed captain, and an instructor at a number of maritime schools in the Seattle area.

Search This Blog

Loading...

Friday, September 28, 2012

If you've ever read the book The Physics of Star Trek by Lawrence M Krauss (and if you haven't, you should!), you already know that in 1994 physicist Miguel Alcubierre proved that a Star Trek-like warp drive was theoretically possible, but would require an insane amount of energy. Interesting, but not altogether useful.

It seems that a solution to this has been found which makes the power requirements for a functional warp drive reasonable and plausible.

The article below, from Space.Com, is poorly organized and disjointed, and appears to have been cut and pasted from a longer press release. Nonetheless, it gives the general sense of the discovery.

If in fact we have the ability to build a drivetrain which propels vessels at speeds which are functionally greater than the speed of light but physically lower than 5% of the speed of light, then interstellar travel is genuinely within our grasp. This research is still in its infancy. But it is the first real indication I've ever seen that we could ever attain supralight transport.

If we can, presumably others can as well. This potentially has enormous ramifications for the Fermi Paradox. Even without supralight drivetrains, the apparent absence of technologically capable extraterrestrial species here on earth is statistically suspect. If warp drive or other technologies can provide feasible faster-than-light travel, the plausibility that we have not been contacted by other worlds becomes vanishingly slim.

SPACE.COM — A warp drive to achieve faster-than-light travel — a concept popularized in television's Star Trek — may not be as unrealistic as once thought, scientists say.

A warp drive would manipulate space-time itself to move a starship, taking advantage of a loophole in the laws of physics that prevent anything from moving faster than light. A concept for a real-life warp drive was suggested in 1994 by Mexican physicist Miguel Alcubierre; however, subsequent calculations found that such a device would require prohibitive amounts of energy.

Now physicists say that adjustments can be made to the proposed warp drive that would enable it to run on significantly less energy, potentially bringing the idea back from the realm of science fiction into science.

An Alcubierre warp drive would involve a football-shape spacecraft attached to a large ring encircling it. This ring, potentially made of exotic matter, would cause space-time to warp around the starship, creating a region of contracted space in front of it and expanded space behind.

Meanwhile, the starship itself would stay inside a bubble of flat space-time that wasn't being warped at all.

"Everything within space is restricted by the speed of light," explained Richard Obousy, president of Icarus Interstellar, a non-profit group of scientists and engineers devoted to pursuing interstellar spaceflight. "But the really cool thing is space-time, the fabric of space, is not limited by the speed of light."

With this concept, the spacecraft would be able to achieve an effective speed of about 10 times the speed of light, all without breaking the cosmic speed limit.

The only problem is, previous studies estimated the warp drive would require a minimum amount of energy about equal to the mass-energy of the planet Jupiter.

But recently White calculated what would happen if the shape of the ring encircling the spacecraft was adjusted into more of a rounded donut, as opposed to a flat ring. He found in that case, the warp drive could be powered by a mass about the size of a spacecraft like the Voyager 1 probe NASA launched in 1977.

Furthermore, if the intensity of the space warps can be oscillated over time, the energy required is reduced even more, White found.

"The findings I presented today change it from impractical to plausible and worth further investigation," White told SPACE.com. "The additional energy reduction realized by oscillating the bubble intensity is an interesting conjecture that we will enjoy looking at in the lab."

White and his colleagues have begun experimenting with a mini version of the warp drive in their laboratory.

They set up what they call the White-Juday Warp Field Interferometer at the Johnson Space Center, essentially creating a laser interferometer that instigates micro versions of space-time warps.

"We're trying to see if we can generate a very tiny instance of this in a tabletop experiment, to try to perturb space-time by one part in 10 million," White said.

He called the project a "humble experiment" compared to what would be needed for a real warp drive, but said it represents a promising first step.

And other scientists stressed that even outlandish-sounding ideas, such as the warp drive, need to be considered if humanity is serious about traveling to other stars.

"If we're ever going to become a true spacefaring civilization, we're going to have to think outside the box a little bit, we're going to have to be a little bit audacious," Obousy said.

Thursday, September 20, 2012

So, for those folk who are just tuning in, a quick recap. NASA is in the process of building the largest and most powerful rocket of all time, which will take human explorers deeper into space than has ever been previously attempted. SLS will take humans to the nearest asteroids, possibly back to the moon, and eventually to Mars. It will be fully flight-ready by 2021, its first uncrewed test flight is scheduled for 2017.

Oh, and NASA is doing all of this with no budget, cannibalizing spare parts from the space shuttles, the Saturn V and the Orion space capsule which was already being designed for the Constellation project, before it got the budgetary axe.

Yes, Virginia, NASA is going to Mars on a rocket built out of bench-spares. More significant is the fact that nearly two years into this project, and nobody outside of the space industry and folks who follow space blogs like this one have any idea that this is happening.

On the one hand, good on NASA for not wasting lots of taxpayer dollars on advertising. But, really? Look at this video. It's not bad. It's fairly informative, even. But it looks like a low-budget shareholder's promo for some second-tier airplane manufacturer. If NASA were churning out videos like this every month or so it would be less surprising, but I think this is the first SLS promo since the original one back in early 2011.

It's not just that the general public isn't enthusiastic about SLS, if they're even aware of it. NASA itself seems pretty luke-warm on the project. This is understandable, it was foisted upon them by a congress who not only didn't have any answers, didn't even comprehend the questions being asked them. And even if they come in on time and under budget (which, so far, seems quite possible), Elon Musk and SpaceX, with the help of NASA subsidies, will probably land humans on Mars before SLS can. So I can understand why NASA might not be pouring their hearts and souls into this project.

But, in spite of all this, I think SLS will be a pretty good platform, at a pretty good price, and I think it will be a real work-horse for inner solar system exploration. The aircraft company who always dreamed of designing the Concorde is instead building a Boeing 737. Of the two, the 737 was arguably the better aircraft, but it was far less sexy. The SLS is about as un-sexy as a spacecraft could possibly be. But it's going to get the job done, better than much of its competition.

NASA, be proud of the work you're doing with SLS. You have a good, solid, robust platform here which will take us to Mars, and possibly beyond. That's not a small thing.

Sunday, September 2, 2012

So, a minor milestone; today Strait of Magellan reached a total of 50,000 page-views. Given that the blog is less than 2 years old, I think that's kind of cool. So to celebrate, I bought this:

Ok, that's a lie, the two have absolutely nothing to do with each other. But this is my new boat, and I like it, and it's my blog so I'm posting it here.

That's right. You can't take the water from me, either.

If you happen to get that last reference, yes the boat was named Serenity before the TV series or movie, and yes we will be redoing the lettering to better reflect the latter. My wife has already found Blue Sun corporate logo fabric for the interior upholstery. Really, she did.

Saturday, September 1, 2012

The ion-powered Dawn spacecraft is about to leave its orbit of the asteroid Vesta, and begin it's mission to the minor planet Ceres. This has been buried in this week's news cycle, but it's really important. Depending on what Dawn finds, Ceres may rocket to the top of the list of candidates for human colonization. Larger than Enceladus but smaller than Europa, Ceres also seems to have a rocky core surrounded by liquid water covered with ice. It lacks the massive radiation from Jupiter that bombards Europa, and is much closer to Earth than either Europa or Enceladus; close enough even for current solar power cells to function. And unlike our moon or Mars, there is plenty, plenty of water.

It will take almost three years for Dawn to reach Ceres. Stay tuned, it may well prove worth the wait.

==================================

PASADENA, Calif. – NASA's Dawn spacecraft is on track to become the first probe to orbit and study two distant solar system destinations, to help scientists answer questions about the formation of our solar system. The spacecraft is scheduled to leave the giant asteroid Vesta on Sept. 4 PDT (Sept. 5 EDT) to start its two-and-a-half-year journey to the dwarf planet Ceres.

Dawn began its 3-billion-mile (5-billion kilometer) odyssey to explore the two most massive objects in the main asteroid belt in 2007. Dawn arrived at Vesta in July 2011 and will reach Ceres in early 2015. Dawn's targets represent two icons of the asteroid belt that have been witness to much of our solar system's history.

To make its escape from Vesta, the spacecraft will spiral away as gently as it arrived, using a special, hyper-efficient system called ion propulsion. Dawn's ion propulsion system uses electricity to ionize xenon to generate thrust. The 12-inch-wide ion thrusters provide less power than conventional engines, but can maintain thrust for months at a time.

"Thrust is engaged, and we are now climbing away from Vesta atop a blue-green pillar of xenon ions," said Marc Rayman, Dawn's chief engineer and mission director, at NASA's Jet Propulsion Laboratory, Pasadena, Calif. "We are feeling somewhat wistful about concluding a fantastically productive and exciting exploration of Vesta, but now have our sights set on dwarf planet Ceres.

Dawn's orbit provided close-up views of Vesta, revealing unprecedented detail about the giant asteroid. The mission revealed that Vesta completely melted in the past, forming a layered body with an iron core. The spacecraft also revealed the scarring from titanic collisions Vesta suffered in its southern hemisphere, surviving not one but two colossal impacts in the last two billion years. Without Dawn, scientists would not have known about the dramatic troughs sculpted around Vesta, which are ripples from the two south polar impacts.

"We went to Vesta to fill in the blanks of our knowledge about the early history of our solar system," said Christopher Russell, Dawn's principal investigator, based at the University of California Los Angeles (UCLA). "Dawn has filled in those pages, and more, revealing to us how special Vesta is as a survivor from the earliest days of the solar system. We can now say with certainty that Vesta resembles a small planet more closely than a typical asteroid."

The mission to Vesta and Ceres is managed by NASA's Jet Propulsion Laboratory in Pasadena, Calif., for the agency's Science Mission Directorate in Washington. Dawn is a project of the directorate's Discovery Program, which is managed by NASA's Marshall Space Flight Center in Huntsville, Ala.

UCLA is responsible for the overall Dawn mission science. Orbital Sciences Corp. of Dulles, Va., designed and built the spacecraft. The German Aerospace Center, the Max Planck Institute for Solar System Research, the Italian Space Agency and the Italian National Astrophysical Institute are part of the mission's team. The California Institute of Technology in Pasadena manages JPL for NASA.

For more information about Dawn, visit: http://www.nasa.gov/dawn and http://dawn.jpl.nasa.gov .